The present invention relates to a piezoelectric vibrator, and more precisely, to a piezoelectric vibrator whose fundamental main vibration mode is the thickness-shear mode such as an AT-cut quartz vibrator, a BT-cut quartz vibrator or a ceramic vibrator.
Generally a quartz vibrator operates in the fundamental main vibration mode and in many spurious vibration modes. In the case that the frequency of the fundamental main vibration is adjacent to the frequency of the spurious vibration, there is a likelihood that the quartz vibrator operate in the spurious vibration mode or be adversely influenced by the spurious vibration.